JPH06105037B2 - Tunnel construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a tunnel construction method by a cast-in-place concrete lining shield method.

(Prior Art) The present applicants extend in the circumferential direction of the tunnel hole at predetermined intervals along the tunnel axial direction on the outer circumference of the inner formwork assembled in the tunnel hole excavated by the shield excavator. A ring-shaped steel plate is arranged, and the ring-shaped steel plate is pressed by a propulsion jack mounted on the excavator, and is driven between the inner formwork and the inner peripheral surface of the tunnel hole through the ring-shaped steel plate. Pressed the lining concrete that was made, and the shield excavator is propelled by using the concrete pressure as a reaction force.
A tunnel construction method has been proposed in which the ring-shaped steel plate is used also as a gable form for lining concrete, a pressure plate, and a tunnel reinforcing material.

(Problems to be Solved by the Invention) In the tunnel construction method, in order to prevent the shield excavator from retracting at the time of installing the ring-shaped steel plate, assembling the inner formwork, placing the lining concrete, etc. I needed a naive jack.

Further, there is a problem that tensile / compressive stress in the tunnel axial direction cannot be sufficiently dealt with after the tunnel lining is completed.

The present invention has been proposed in view of the problems of the tunnel construction method, and an object of the present invention is to reliably support a retreat pressure applied to a shield excavator at the time of relocating a jack and to perform a lining. The point is to provide a tunnel construction method that improves the strength and rigidity of concrete.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the tunnel construction method according to the present invention allows a reaction force supporting steel rod to penetrate through the ring-shaped steel plate while a locking member is fixed to the outer peripheral portion. The tip of the steel rod
A guide cylinder is provided slidably on the back surface of the steel rod penetrating hole of the ring-shaped steel plate and has an inner peripheral surface with a locking projection so as to be slidably inserted, and the backward pressure applied to the excavator is adjusted by the guide cylinder. The locking projection is supported by the locking member of the reaction force supporting steel bar, and when the shield excavator is propelled, the locking projection and the locking member are unlocked, The ring-shaped steel plate is configured to be pressed by the propulsion jack until the locking member collides with the ring-shaped steel plate.

(Operation) Since the method of the present invention is configured as described above, when a retreating pressure acts on the shield excavator during installation of the ring-shaped steel plate, assembly of the inner formwork, pouring of lining concrete, etc. A locking projection projecting from an inner periphery of a guide cylinder projecting from a rear surface of a through hole of a reaction force supporting rod in the ring-shaped steel plate, and the reaction force support slidably inserted in the guide cylinder. The retracting pressure applied to the excavator is supported by the engagement with the engagement protrusion fixed to the outer circumference of the tip of the rod.

Thus, when the shield excavator is propelled, the engagement between the engagement protrusion of the guide cylinder and the engagement member of the reaction force supporting steel rod is released, the ring-shaped steel plate is pressed by the propulsion jack, and the reaction force supporting steel is Retreat along the rod until it hits the locking member of the steel rod, pressurize the lining concrete placed between the inner formwork and the tunnel hole to fill the tail void, and The shield excavator is propelled using the pressure reaction force as the propulsion reaction force.

(Examples) The present invention will be described below with reference to illustrated examples.

1 to 7 show a first embodiment of the present invention,
(1) is a tail plate of the shield excavator, (2) is an inner formwork assembled in a tunnel hole formed by the excavation of the excavator, and (3) is a tunnel axis direction on the outer periphery of the inner formwork. , Ring-shaped steel plates arranged at predetermined intervals, (4) is a reaction-force-supporting steel rod freely penetrated by the steel plate (3), and (5) is cast on the outer periphery of the inner mold (2). It is lining concrete.

A guide cylinder (6) communicating with the through hole (3a) of the reaction force supporting steel rod in the ring-shaped steel plate (3) is connected to the hole (3a).
Is projected in the axial direction of the tunnel, and a locking projection (7) is projected on the inner peripheral surface, and the guide tube (6) is slidable on the outer periphery of the tip of the reaction force supporting steel rod (4). An annular locking member (8) that fits in is projected.

Then, the tip of the reaction force supporting steel rod (4) is fitted into the guide tube (6) of the ring-shaped steel plate (3), and the reaction force is applied to the locking projection (7) of the guide tube (6). By locking the locking member (8) of the supporting steel rod (4), the inner formwork (2) is assembled while supporting the retreat pressure applied to the shield excavator at the time of rearranging the jack, and the next lining is constructed. A concrete pouring space (9) is formed. (See Fig. 1, Fig. 5 and Fig. 6) After placing the lining concrete (5) in the space (9) (see Fig. 2), the jack of the shield excavator (1)
0) is extended and the shield excavator is propelled while pressurizing the concrete (5).

With the start of propulsion of the shield excavator, the locking projection (7) of the guide tube (6) on the ring-shaped steel plate (3) is broken off by the strong pressing force of the shield jack (10), and the reaction force supporting steel. The ring-shaped steel plate (3) is attached to the existing lining side so that the tip of the rod (4) penetrates into the through hole (3a) of the ring-shaped steel plate (3).
The concrete is slid until it hits the locking member (8), and the concrete (5) is pressed, and the shield excavator is propelled using this concrete pressure as a reaction force.

(See FIGS. 3 and 7) Since the final pushing position of the ring-shaped steel plate (3) is automatically determined by the locking member (8) of the reaction force supporting steel rod (4), the ring-shaped steel plate is shown. (3) will be installed at equal intervals.

Thus, push the ring-shaped steel plate (3) to a predetermined position,
When the propulsion of the shield excavator for one span is completed, the reaction force supporting steel rods (4) of the next span are connected by the steel rod connecting material (11) such as joint nuts and couplers, and the ring-shaped steel plate (3) )
Replace the jack while installing. (See FIG. 4) A tunnel is constructed by repeating the same steps as described above.

Thus, the reaction supporting steel rods (4) embedded in the lining concrete (5) so as to extend in the tunnel axial direction improve the rigidity of the lining concrete (5) in the tunnel axial direction. In addition to the fact that the ring-shaped steel plates (3) are embedded in the lining concrete (5) at exactly predetermined intervals, the quality of the concrete is stabilized.

8 to 15 show a second embodiment of the present invention, in which the guide tube (12) has a bearing (13) in the reaction force supporting steel rod through hole (3a) of the ring-shaped steel plate (3). The guide cylinder (12) is rotatably fitted with the locking projections (14) at predetermined intervals on the inner peripheral surface of the rear part thereof. In the illustrated embodiment, the locking projections (14) are arranged at 90 ° intervals. (See FIG. 13) A ring-shaped stopper (15) is projectingly provided on the inner peripheral surface of the front part of the guide cylinder (12). (Refer to FIG. 14) On the outer periphery of the tip of the reaction force supporting steel rod (4), a locking member (16) that engages and disengages with the locking projection (14) as the guide tube (12) rotates.
Is fixed.

In the illustrated embodiment, the outer peripheral surface of the ring-shaped locking member (16) is
The recesses are arranged at intervals of 90 °, and the locking member (16) and the locking projection (14) are disengaged by rotating the guide cylinder (12) by 45 °. (See FIG. 13) In the figure, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals.

Then, the tip end of the reaction force supporting steel rod (4) is fitted into the guide cylinder (12) of the ring-shaped steel plate (3), and the guide cylinder (1
By locking the locking member (16) of the reaction force supporting steel rod (4) to the locking projection (14) of 2), the retracting pressure applied to the shield excavator at the time of rearranging the jack is supported while supporting the internal force. The formwork (2) is assembled to form a lining concrete placing space (9). (See FIGS. 8 and 12) Next, concrete (5) is placed in the same space (9), and then the guide cylinder (12) is rotated 45 ° as shown in FIG. 13 to engage the locking projection (14). After releasing the locking between the locking member (16) and the locking member (16) (see FIG. 9), the propulsion jack (10) is extended,
The ring-shaped steel plate (3) slides toward the existing lining side so that the tip of the reaction force supporting steel rod (4) penetrates into the through hole (3a) of the ring-shaped steel plate (3), (See Fig. 10) Pressurize the poured concrete (5). The shield excavator is propelled by using this concrete pressure as a propulsion reaction force, and finally the stopper member (16) of the reaction force supporting steel rod (4) is engaged with the stopper (15) of the guide cylinder (12). However, the final pushing position of the ring-shaped steel plate (3) is automatically determined, and the ring-shaped steel plates (3) are completely installed at equal intervals.

Thus, push the ring-shaped steel plate (3) to a predetermined position,
When the propulsion of the shield excavator for the span is completed, the reaction force supporting steel rod (4) of the next span is connected through the steel rod connecting material (11) such as the joint nut and the coupler, and the ring-shaped steel plate ( 3) Install and replace the jacks one after another. (No. 11
(Refer to the drawing) Hereinafter, a tunnel is constructed by repeating the same steps as described above.

(Effects of the Invention) According to the present invention, a reaction force is exerted on the ring-shaped steel plate arranged on the outer periphery of the inner lining concrete formwork assembled inside the tunnel hole excavated by the shield excavator as described above. A locking member that penetrates the supporting steel rod and is fixed to the outer circumference of the steel rod tip can be applied to a guide tube that is provided on the rear surface of the steel rod through hole of the ring-shaped steel plate and has a locking protrusion on the inner peripheral surface. By slidingly inserting and locking the locking member and the locking projection, the retracting pressure applied to the shield excavator at the time of exchanging the jack is reliably supported, and the jack for supporting the retracting pressure is provided. It is possible to improve workability by eliminating the need for special provision.

When the shield excavator is propelled, the locking projection is disengaged from the locking member, and the reaction force supporting steel rod is pressed against the ring steel plate by the propelling jack until the reaction force supporting steel rod collides against the ring steel plate. The cast lining concrete can be pressurized without being hindered by the supporting steel rods, and the shield excavator can be propelled by using the concrete pressure as a propulsive reaction force.

Further, the reaction force supporting steel rod is embedded in the lining concrete in the tunnel axial direction to increase the rigidity in the tunnel axial direction.

[Brief description of drawings]

1 to 4 are longitudinal sectional views showing steps of an embodiment of a tunnel construction method according to the present invention, and FIG. 5 is a reaction force supporting steel rod and a ring-shaped steel plate at the time of supporting backward pressure applied to a shield excavator. FIG. 6 is a vertical cross-sectional view showing the relationship between the reaction force supporting steel rod and the ring-shaped steel plate when the shield excavator is propelled, and FIG. 11 to 11 are longitudinal sectional views showing steps of another embodiment of the tunnel construction method according to the present invention, and FIG. 12 is a reaction force supporting steel rod and a ring-shaped steel plate at the time of supporting backward pressure applied to the shield excavator. FIG. 13 is a longitudinal sectional view showing the relationship, FIG. 13 and FIG. 14 are longitudinal side views of the rear side as well as the front side, respectively, and FIG. 15 is a reaction force supporting steel rod and a ring-shaped steel plate at the time of propulsion of the shield excavator. It is a vertical side view which shows a relationship. (1) ... Tail plate, (2) ... Inner form, (3) ... Ring steel plate, (3a) ... Through hole of reaction force supporting steel rod, (4) ... Reaction force supporting steel rod, (5) ... Concrete, (6) ... Guide tube, (7) ... Locking projection, (8) ... Locking member, (10) ... Propulsion jack, (12) ... Guide tube, (14) ... Locking projection,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-21989 (JP, A) JP 62-211445 (JP, A) JP 64-043698 (JP, A) JP 42- 5785 (JP, B1)

Claims (1)

[Claims] 1. A ring-shaped steel plate extending in the circumferential direction at predetermined intervals along the tunnel axial direction is provided on the outer circumference of an inner formwork assembled in a tunnel hole excavated by a shield excavator. , The ring-shaped steel plate is pressed by a propulsion jack mounted on the excavator, the lining concrete placed on the outer periphery of the inner formwork is pressed through the ring-shaped steel plate, and the concrete pressure is applied. In a tunnel construction method in which a shield excavator is propelled as a propulsion reaction force, a reaction force supporting steel rod is loosely penetrated into the ring-shaped steel plate, and the tip of the steel rod having a locking member fixed to the outer peripheral portion is formed into the ring. -Shaped steel plate is slidably fitted into a guide cylinder having a locking projection on its inner peripheral surface and protruding from the rear surface of the steel rod through-hole, and the retraction pressure applied to the excavator is locked by the locking projection of the guide cylinder. And reaction force supporting steel rod locking part When the shield excavator is propelled, the locking projection and the locking member are unlocked, and the locking member of the reaction force supporting steel bar is struck until it abuts the ring-shaped steel plate. A method for constructing a tunnel, which comprises pressurizing a ring-shaped steel plate with a propelling jack.